McLaren power-unit issue lingers at Spa after Stella flags deployment problem
NXTbets Pro | Published On: July 19, 2026
McLaren deployment issues
McLaren spent Friday at Spa-Francorchamps chasing answers from its latest Mercedes power unit, and Andrea Stella said small differences in power unit operation and energy deployment shaped the pace around the Belgian Grand Prix weekend. The team started receiving Mercedes power unit simulation tools, and Stella said the access has already improved McLaren’s preparation and performance as a customer team. He pointed to the weekend at Spa as a clear example of those benefits, but he also said the same data had exposed how finely balanced the package remains when the team looks at deployment and energy use over a lap. After qualifying, McLaren was investigating inconsistent electrical energy deployment from the unit, and Stella said the session marked a step forward without solving the underlying issue. He said McLaren still needs to close the gap to Mercedes and build a better understanding of the hybrid system’s deployment if it wants to keep sharpening its pace. That leaves the team with useful information from Spa and a fresh technical problem to solve. The core issue sits in the details of how the power unit gives up energy, when it deploys it and how that affects straight-line speed and lap time. Stella made clear that the fine margins matter at a circuit like Spa, where small changes in delivery can show up quickly on the stopwatch.
Piastri pace questions
Oscar Piastri’s qualifying loss to Lando Norris drew Stella’s attention to the power unit rather than the driver, and he said the gap was mainly caused by straight-line energy deployment. Stella said the issue may have come from factors outside the drivers’ control, which put the focus on the car’s electrical delivery rather than Piastri’s lap execution. The main time loss came on the straight between Stavelot and the Bus Stop Chicane during the derating phase, where the car gave away speed and left Piastri with less room to fight for position. Stella also said he suspected George Russell’s unexplained straight-line gap to Kimi Antonelli may have had a similar cause, which reinforced his view that Spa’s long straights were exposing the same kind of deployment problem in more than one car. Piastri qualified seventh, but his day had already been disrupted on Friday when a hydraulic leak forced a gearbox change and delayed his return for second practice. That setback added pressure to the rest of his weekend, and he later ran wide and hit gravel in Q3. The sequence left McLaren with a clearer picture of how many moving parts were affecting Piastri’s performance, from the earlier hydraulic issue to the energy deployment problem that Stella believes hurt him in qualifying. The team did not frame the performance gap as a driving mistake. It treated it as a technical problem that showed up at the worst possible points around the lap.
Norris penalty outlook
Lando Norris qualified third at Spa-Francorchamps, but his grid position will drop to 13th after McLaren fitted him with a fourth power electronics unit and handed him a 10-place grid penalty. That penalty adds another layer to a weekend already defined by technical issues and energy deployment concerns for McLaren. Norris’s pace in qualifying showed the car still had speed, yet the team’s wider problem with the hybrid system has clouded the picture around both drivers. Stella’s comments suggest the crew sees the qualifying effort as progress, even if it did not settle the questions around how the Mercedes power unit is delivering energy. Technical director Neil Houldey said McLaren would spend the night refining energy deployment and reliability before FP3 and qualifying, which shows where the team plans to put its effort next. The work sits at the intersection of performance and durability, with McLaren trying to improve the way the car uses energy while also protecting itself against the kind of reliability headaches that can force penalties and race-day compromises. Norris’s situation underlines that point. A strong qualifying result means less when the car also needs a fresh component and a start from the middle of the pack. McLaren now has to balance the immediate need to recover lost grid positions with the longer task of understanding why Spa exposed so many differences in its power-unit operation.
